User guide# User guide Introduction Initialize the Simulation State Initialize the Simulation System Run the Simulation Saving the Simulation State The Simulation State State Creation Modifying State Attributes Extending the State Merging Two States Stacking States for Trajectories or Batches Trajectories of Batches Utilities The Simulation System System Creation Configuring the System Manually swapping a submodule Time stepping Trajectory rollout Batched simulations with vmap